Clinical Consult: ADHD

More than 50 years of epidemiologic research indicates that attention-deficit hyperactivity disorder (ADHD) affects 5 to 7 percent of the population. While there are “islands” of over-diagnosis—among boys, nonwhite children and children at the highest and lowest ends of the socioeconomic spectrum—most other ADHD is under-diagnosed, including in girls.

With time and care, ADHD can certainly be diagnosed and managed in a primary care setting. Pediatricians can be patients’ best advocates, helping children receive support services and appropriate testing and interventions at school.

ADHD and the DSM-V

The DSM divides ADHD into three groups: attention disorders with a predominantly hyperactive/impulsive presentation, a predominantly inattentive presentation and a combined type. To meet ADHD criteria, children must show more of the behavior than is usual for age, the symptoms must be causing problems and there must be no other neurologic or psychiatric explanation.

The DSM-V has made it harder to over-diagnose ADHD. As in the DSM-IV-TR, symptoms of inattention or hyperactivity/impulsivity must be present in two different situations. But the DSM-V adds the requirement for two observers (usually a parent and a teacher) to report symptoms. In our experience, a diagnosis cannot be made confidently without input from both home and school settings.

The DSM-V also allows for symptom onset up to 12 years of age (the previous cutoff under DSM-IV-TR was age 7). This casts a wider net for making the diagnosis. However, in older children, certain later-onset neurometabolic disorders (such as adrenoleukodystrophy) can initially present with ADHD-like symptoms and should be considered as part of the differential diagnosis under appropriate clinical circumstances.

Primary care evaluation for ADHD

The first step is a careful patient and family history and a general exam to rule out medical conditions with symptoms that can mimic ADHD. Children who use drugs or alcohol or who have been physically or sexually abused can also present with ADHD-like symptoms, and comorbid psychiatric disorders can complicate the picture. These possibilities should be considered.

The next step should be a clinical exam with tests to investigate attention, language and visuospatial function. Significant language or visuospatial dysfunction should make you question a diagnosis of ADHD and lead to referral.

ADHD questionnaires

A variety of standardized questionnaires with norms for different ages are available to help you assess ADHD symptoms. No single questionnaire is ideal, but they can be used in combination, tailored to the child’s history. Most have components for both parents and teachers. Among the more helpful rating scales:

The Conners, Vanderbilt and DuPaul scales are quick, easy to use and good for identifying clinically significant hyperactivity and inattention. They are less useful in patients with comorbid psychiatric conditions that can intermingle with ADHD.

The Child Behavior Checklist (CBCL), available for different age groups, is good for identifying comorbid conditions and can elicit some useful historical information. It is less useful for assessing hyperactivity.

Medical treatment for ADHD

Three studies from very different settings have concluded that children do best with combined medical and behavioral treatment. Presynaptic dopaminergic stimulants are the first line of medical therapy. There are two types, dispensed in various formulations:

Methylphenidate-derived (Ritalin, Concerta, etc.): Patients should start with a low dose (0.5 mg/kg/day), increased to up to 1.5 mg/kg/d depending on their response. Duration of action is usually 3 to 4 hours.

Amphetamine-derived (Adderall, Dexedrine, Vyvanase, etc.): Start at 0.25 mg/kg/day, increasing to up to 0.75 mg/kg/d as response indicates. Duration of action is usually 2 to 3 hours. You may need to try more than one amphetamine medication. A newer option is lisdexamfetamine, usually dosed at 1 mg/kg/d.

Both types of stimulant can affect growth and produce side effects (headache, appetite reduction, stomach discomfort, tachycardia, hypertension, tics, and, rarely, hallucinations, seizures and movement disorders). We suggest starting with one class, adjusting the dose, and, if poorly tolerated, switching to the other class. Starting with an agent with which you are familiar is always a good strategy.

As a second-line agent, atomoxetine (a selective norepinephrine reuptake inhibitor) has been shown to improve symptoms in roughly 70 percent of children not helped by stimulants. Of note, it can cause liver dysfunction. The starting dose is 0.5 mg/kg/d; after about a week, advance to 1.2 mg/kg/d. This can be split into two doses if the response is poorly sustained.

There are also third-tier agents:

Alpha-adrenergic agents (clonidine, guanfacine), can be helpful if the child has tics or significant impulsivity, but are less helpful for hyperactivity.

Mixed serotonin/norepinephrine reuptake inhibitors (e.g., venlafaxine) can be helpful in children with comorbid anxiety or depression.

Aminoketones (e.g., bupropion) can be helpful in depression.

Behavioral treatment

Cognitive behavioral therapy can be a very useful concomitant treatment for children with ADHD, and may be particularly useful for organizational strategies, behavioral impulsivity and task stratification.